Adhesive applying device



5 Sheets-Sheet 1 Filed Sept. 23, 1964 INVENTOR. eoffrey F Dobbyn 1967 G.F. DOBBYN ADHESIVE APPLYING DEVICE 5 Sheets-Sheet 2 Filed Sept. 23, 1964INVENTOR. fey/ Dobbyn ed, ("M

| I" l I l TTOE/YEY Oct. 17, 1967 G. F. DOBBYN 3,347,205

ADHESIVE APPLYING DEVICE Filed Sept. 23, 1964 5 Sheets-Sheei 5 M s MINVENTOR. Geoffrey l-TDobbyn BY GL -MQ W ATTO/Z/YE'Y Oct. 17, 1967 G. F.DOBBYN ADHESIVE APPLYING DEVICE 5 Sheets-Sheet Filed Sept. 25, 1964 INVENTOR Geoffrey FDabbyn BY {MeL M A T7OENEY United States Patent Ofilice3,347,205 Patented Get. 17, 1967 3,347,205 ADHESIVE AIPLYING DEVICEGeoffrey F. Dohbyn, Braintree, Mass., assignor to Pneumatic ScaleCorporation, Limited, Quincy, Mass., a corporation of MassachusettsFiled Sept. 23, 1964, Ser. No. 398,497 Ciairns. (Cl. 118-7) ABSTRACT OFTHE DISCLOSURE A device for applying quick-setting adhesive to thecarton closing flaps of a filled carton. Liquid adhesive is transferredto a heated applying roll from a heated melt chamber which receives itssupply in solid form. Control means detects depletion of adhesive in thesupply to replenish the same.

This invention relates to an adhesive applying device particularlyadapted for use in a packaging machine.

The invention has for an object to provide a novel and improved adhesiveapplying device of the character specified having novel provision forautomatically maintaining a substantially uniform supply of adhesive inresponse to the demand therefor.

The invention has for a further object to provide a novel and improvedadhesive applying device particularly adapted for handling aquick-setting adhesive, such as a microcrystalline wax emulsion whereinsolid pellets of adhesive are automatically fed into a melting chamberto provide a substantially uniform supply of liquefied adhesive inresponse to the demand therefor.

Vv ith this general object in view and such others as may hereinafterappear, the invention consists in the adhesive applying device and inthe various structures, arrangements and combinations of partshereinafter described and particularly defined in the claims at the endof this specification. I

In the drawings illustrating the preferred embodiment of the invention:

FIG. 1 is a side elevation of the present adhesive applying device shownas embodied in a packaging machine having provision for closing andsealing the top closing flaps of a carton;

FIG. 2 is a plan view of the device, some of the parts being shown incross section;

FIG. 3 is an end view partly in cross section of the device as seen fromthe left hand side of FIG. 1;

FIG. 4 is a plan view of a carton showing the side closin g flapsextended laterally and the end closing flaps folded inwardly, three ofthe flaps being provided with spots of adhesive as applied by thepresent device;

FIG. 5 is a front elevation of the same showing the applying roll;

FIG. 6 is a wiring diagram of a control circuit to be described; and

FIG. 7 is a cross sectional detail view of the glue pot on an enlargedscale showing the melting chamber and adhesive transfer mechanismsupplying adhesive to the applying roll.

In general, the present invention contemplates a novel adhesive applyingdevice particularly adapted for use in a packaging machine, herein shownas arranged to apply adhesive to selected top closing flaps of a filledcarton, which flaps are thereafter closed into adhesive engagement toseal the top closure. Prior to the present invention a liquid type ofadhesive having a relatively slow setting or drying time was used. As aconsequence it was required to pass the carton through an elongateddryer which consists of spaced upper and lower belts between which theends of the cartons are supported and advanced to hold the adhesivelycoated flaps down a suflicient length of time to permit the adhesive todry to set the seal. With the advent of high speed packaging machinerythe length of the dryer had tobe increased to unwieldly proportions toallow suflicient time to permit the adhesive to set.

In accordance with one feature of the present invention, in order toreduce the drying time and consequently the length of the dryer, or toeliminate entirely the need for a dryer in a high speed packagingmachine, provision is made for applying to the top closing flaps aquick-setting hot melt adhesive, such as a microcrystalline waX emulsionwhich is capable of drying and setting up quickly after the flaps areclosed and slight pressure applied for a relatively short time toprovide an efficient top closure seal.

In practice, the hot melt adhesive must be kept at a relatively hightemperature, about 350 F., to maintain it in a liquefied form sufiicientto prevent thickening and to permit easy handling during transfer fromthe supply to the adhesive applying roller and from the latter to thecarton flaps. The hot melt adhesive also has a relatively high settingor hardening temperature, which is about 200 F. Furthermore, in a highspeed packaging machine, capable of producing sealed containers at therate of about containers a minute, for example, the supply of adhesiveis rapidly depleted so as to require constant attention by the operatorto replenish the supply.

In accordance with another feature of the present invention provision ismade for automatically replenishing the supply of adhesive in responseto the demand therefor. In the illustrated embodiment of the invention,the hot melt adhesive is supplied in a solid form, such as in the formof pellets, which may be fed at a uniform rate to a melting chamber toliquefy the adhesive. The liquefied adhesive is arranged to flow fromthe melting chamber into an adhesive supply chamber. The supply chamberis provided with means for detecting the height of the liquid adhesivein the chamber, and when the height of the liquid is reduced below apredetermined level provision is made for initiating the feed of thepellets into the melting pot. Conversely, when the height of the liquidin the adhesive chamber is increased to said predetermined level thefeed of the pellets is discontinued.

Referring now to the drawings, in general the present adhesive applyingdevice comprises an adhesive supply hopper 10 arranged to supplyadhesive in the form of solid pellets 12 to a vibratory feeder indicatedgenerally at 14. The vibratory feeder 14 is arranged to feed the pelletsin a uniform stream into a heated melting chamber 16 mounted on a casing18 above an adhesive supply chamber 20. The bottom wall of the meltingchamber 16 is perforated as indicated at 21 so that the liquefiedadhesive will flow from the melting chamber through the perforations andinto the liquid adhesive chamber. The liquid adhesive is transferredfrom the chamber 20 onto an applying roll 22 by a transfer wheel 24 anda spreader roll 26. The applying roll 22 is continuously rotated intimed relation to the advance of the cartons 28 along a conveyer 30, andselected of the top closing flaps of the cartons are provided with spotsof adhesive during the continuous movement of the cartons.

As illustrated in FIGS. 2 and 3, provision is made for sensing theheight of the liquid in the liquid adhesive chamber 26 by detectingmeans indicated generally at 32, and a photoelectric switch 34 actuatedby movement of the detecting means and included in a circuit to thevibratory feeder 14 is arranged to control the pellet feeding operationin response to the demand for adhesive.

The conveyor 30 along which the cartons are sup ported advanced may forma part of a packaging machine, such as top closing machine, wherein thecartons are supported by stationary bottom rails 36 and side rails 37and are advanced by spaced pusher arms 38 carried 1 by a continuouslymoving metal belt 40. As herein shown, the metal belt 40 is supported ina grooved track 42 formed by upper and lower extension bracket 44, 4-6attached to the machine frame in a manner similar to that shown anddescribed in the United State patent to Bergeron et al., No. 2,996,855,issued Aug. 22, 1961, to which reference may be made, As alsoillustrated and described in the Bergeron et al. patent, prior to beingadvanced into operative relation to the adhesive applying roll 22 thecarton closing flaps are folded to assume the condition shown in FIG. 4wherein the side Wall flaps 48, 50 are spread outwardly at right anglesto the top of the carton, and the end wall flaps 52, 54 are foldedinwardly on top of the carton. The flaps are maintained in such foldedcondition during the advance of the carton to the adhesive applying roll22 by suitable guide rails 56.

The adhesive applying roll 22 which is rotated at a peripheralspeedequal to the linear speed of the cartons is provided with aplurality of conical openings arranged in a pattern as shown in FIGS. 4and 5, the conical opening carrying adhesive so that when the carton isadvanced into operative relation to the roll selected 'of the cartonflaps will be provided with spots of adhesive. It will be understoodthat the remainder of the applying roll, is scraped free of adhesive aswill be described. As indicated in FIG. 4, the end wall flaps 52, 54folded on top of the filled carton will be provided with adhesive spots58, 6t and the remaining side wall flap 48 will be provided withadhesive spots 62, the remaining side wall flap 50 being free ofadhesive. Pressure of the applying roll 22 against the top of the filledcarton is suflicient to effect transfer of the glue from the conicalopenings to the end wall flaps 52, 54. However, the laterally extendedside wall flap 48 is supported on its underside by a roller 64 carriedby an arm 66 pivotally mounted at 63 in a bracket 70 secured to a plate76 extending from the underside of a supporting bracket 77. A second arm72 integral with the arm 66 is arranged to be urged downwardly so as tocause the roller 64 to press upwardly toward the applying roll 22. Asshown herein, a stud 74 extends through a clearance opening in the arm72, the stud being threadedly secured in a lateral extension 75. Acompression spring 73is coiled about the stud between the upper face ofthe arm 72 and the underside of the extension 75. The head of the stud74 limits the downward movement of the arm 72. It will be observed thatthe pressure roller 64 is provided with a grooved portion 84 whichstraddles the row at conical adhesive applying openings 63 in the roll22 so that the roller 64 will not pick up adhesive when no cartons arepassing through.

After the adhesive spots have been applied to the flaps, as described,the adhesive-free side wall flap 59 is first folded over on top of theend wall flaps 52, 54 to be adhesively secured thereto by the adhesivespots 58, 6t]. Thereafter, the remaining side wall flap 48 is providedwith the adhesive spots 62 is foldedover on top of the adhesive-free.flap to adhesively secure the last' folded flap. The flap closingoperation may be performed during the continued movement of the cartonby stationary curved folding rails indicated at 86, 88 in a conventionalmanner, as shown in FIG. 1, and as also shown in the Bergeron et al.patent above referred to. After the flaps have been closed, pressure maybe applied to the top of the carton in any usual or preferred manner,such as by pressure rolls 89 arranged in the path of the cartons.

As shown in FIG. 2, the adhesive applying roll 22 is arranged to berotated in timed relation to the movement of the cartons throughconnections adapted to be driven from the packaging machine. The roll 22is keyed to one end of a shaft 9t), the other end of the shaft beingconnected by bevel gears 92, 94 to a shaft 96 arranged to be driventhrough a chain and sprocket drive 98 connected to a drive shaft of thepackaging machine, not shown.

Referring now to FIG. 1 for a more detailed description of the pelletfeeding mechanism, the vibratory feeder 14 is arranged to receive thesolid pellets of adhesive 12 by gravity from the supply hopper 10 ascontrolled by an adjustable plate 100 secured to the front wall of thehopper outlet. The vibratory feeder may be of the type capable offeeding a substantially uniform stream of pellets at a constant rate ofspeed and, as herein shown, may comprise a horizontally extended trough102 supported by thin flexible metal straps or leaf springs 104 securedto a platen 106 extended from a frame member 168. The trough 102 isarranged to be vibrated by a vibratory motor 110 which is also securedtothe platen 106. The vibratory motor 110 is included in a circuit shownin FIG. 6 which also includs a rheostat RHI and a rectifier RECI, andthe motor is arranged to be automatically started and stopped inresponse to the demand for adhesive as will be described.

It will be observed that the outlet end of the trough 162 is providedwith a depending lip 112. In operation, prior to the addition of the lip112, some of the pellets at the front edge of the bottom wall of thetrough which might be presoftened by the heat rising from the meltingchamber 16 would have a tendency to stick to such front edge, and theprovision of the depending lip 112 .was found to be conducive to a freeflow of the pellets. The pellets 12 discharged from the outlet end ofthe trough 102 fall by gravity through a funnel 113 and into the mein-gchamber 16. As herein shown, the melting chamber 16 is heated bythermostatically controlled heating cartridges 114, 116 which extendinto the relatively thick chamber walls 118, 120. A thermostat indicatedat T53 in FIG. 3 is also extended into the chamber wall 118forcontrolling the heat of the melting chamber. The solid pellets 12 areliquefied in the melting chamber, and the liquid adhesive flows throughthe openings 21 in the bottom wall of the melting chamber and into theliquid adhesive chamber 20.

As illustrated in FIG. 3, the liquid chamber 20 is elongated andprovided at one end, immediately below the melting chamber 16, with arelatively thick inclined wall 122 down which the melted adhesive flowsinto a well portion 124 of the liquid chamber where the adhesive isaccumulated and from which the adhesive is picked up and transferred tothe applying roll 22. The relatively thick inclined wall 122 is alsoheated by cartridge heaters 126, 128 and 130 which extend through thewall, and a cartridge heater 132 is disposed in a thickened portion 133at one corner of the well portion 124. A thermostat TS2 extended intothe lower end of the inclined wall 122 is provided for controlling thetemperature of the liquid chamber 20.

As shown in FIG. 7, the adhesive pickup wheel 24 comprises a relativelythin plate having a plurality of radially extended arms 136 which dipinto the liquid adhesive as the wheel is rotated and transfer arelatively small amount of liquid adhesive onto the spreader roll 26. The spreader roll 26 is rotated in close contact with the applying roll22 and in cooperation with the latter spreads an even film of adhesiveover the entire area of the applying roll and fills the conical openings63, 65 in the roll with adhesive, the film of adhesive beingsubsequently scraped ofi clean,

leaving the adhesive in the conical openings. As illustrated in FIGS. 2and 3, the spreader roll 26 is driven from the shaft 90 through spurgears 140, 152, the latter being fast on the spreader roll shaft 144,and the pickup wheel 24 is rotated by a spur gear 146 on the shaft 144which is in mesh with a spur gear 148 fast on the pickup wheel shaft150.

As illustrated in FIG. 2, the adhmive applying roll 22 extends forwardlyof the liquid adhesive chamber 20 and is embraced at its upper end byside scrapers 152, 154 extended forwardly from the adhesive chamber. Theside scrapers serve to contain the adhesive from leaking over the sidesof the roll and also serve to guide the surplus adhesive back into theliquid adhesive chamber. The side scrapers may be adjustably mounted tofit snugly against the sides of the roll as shown. The face of theapplying roll 22 is arranged to be scraped substantially free ofadhesive by an adjustable scraper bar 156 which meets the face of theroll at an angle providing a pocket 153 defined by the periphery of theroll and the end of the scraper bar. This expedient serves to scrape theface of the roll clean without reducing the amount of adhesive retainedby the conical openings 63, 65 so as to effect eflicient application ofthe spots of adhesive to the carton flaps as described. The scraper bar156 extends the full width of the roll 22 and cooperates with the sidescrapers 152, 154 to return the surplus adhesive to the liquid chamber.

Referring now to FIG. 2, provision is also made for heating the applyingroll 22. As herein shown, the applying roll is hollow and is providedwith an elongated hollow sleeve 160 mounted for rotation in a bearingformed in the bracket 77. The bracket 77 is secured to a supportingbracket 108 attached to the machine frame. A coiled heating tube 164 isdisposed within the hollow portion of the applying roll 22, and the endsthereof extend through and are supported within an elongated stationarysleeve 166 extended within the rotary sleeve 160. The stationary sleeve166 is formed integrally with a flange 168 which is bolted to thebearing bracket 77. A housing 170 also formed integrally with the flange168 is provided for mounting and connecting the terminals of the heatingtube 164. Thus, in operation, the applying roll 22 is maintained in aheated condition during the application of adhesive to the carton flaps.

As shown in FIGS. 1 and 2, a supporting bracket 175 attached to thebracket 168 extends over the top of the applying roll 22, and extensionstherefrom serve to support the spreader roll 26 and the side scrapers152, 154. The expedient of mounting the spreader roll and the scrapersso as to be supported above the applying roll and independently of theadhesive chamber 20 permits the casing 18 to be disassembled and removedfor clean ing purposes with minimum interference. It will be observedthat the spreader roll shaft 144 is journaled in eccentric bearings 178,180 mounted for rotary adjustment to adjust the spreader roll 26relative to the applying roll 22. Also, the upper wall of the bracket175 is provided with an opening covered by a hinged door 176 forconvenience of the operator to examine the condition of the adhesiveduring the operation of the machine. As also indicated in FIGS. 1 and 2,the pickup Wheel 24 is provided with a housing 177 mounted within thecasing 18 as shown.

Referring now to FIGS. 2 and 3, the control mechanism 32 for controllingthe feed of the pellets in response to the demand for adhesive includesa hollow ball 184 which floats in the adhesive in the Well portion 124of the liquid adhesive chamber 20. The ball is connected to one arm 186of a two-armed lever pivotally mounted between trunnion screws 138, 190.As illustrated, the arm 186 extends through a clearance opening in thechamber casing 18. The second arm 192 of the two-armed lever is arrangedto cooperate with the photoeleectric switch indicated at 34 whichincludes a photocell 194 and a light source 196. The arm 192 is providedwith a plate 198 arranged to intercept or cut off the beam of light. Thephotoelectric switch 34 is included in the circuit to the vibratorymotor 110, as shown in the wiring diagram, FIG. 6, and in operation whenthe adhesive is depleted below a predetermined level in the well portion124, the plate 198 is moved out of the path of the light beam, at whichtime the vibratory motor 110 is energized to start the feedingoperation. Conversely, when the level of the adhesive is restored to apredetermined higher level, the plate 198 will be moved to intercept thelight beam to deenergize the vibratory motor and discontinue the feedingoperation.

As illustrated in FIG. 6, one circuit indicated at 290 comprises a partof the main drive motor circuit, and another circuit indicated at 202indicates the vibratory motor circuit which includes the photoelectricswitch 34. The vibratory motor circuit 262 also includes relay contactsM1 which are closed when the main machine motor is started by pressingpush button PBI. The vibratory motor circuit 262 further includes aswitch SSW3 having contacts 268 in the main motor circuit 290 andcontacts 21d in the vibratory motor circuit 262. The switch SSW3 isarranged to be operated to open the contacts 208 in the main motorcircuit and close the contacts 210 in the vibratory motor circuit bymanual operation of a clutch, not shown, connecting the drive from themain machine to the chain and sprocket drive connection 98. Asillustrated, a by-pass line 212 in the main motor circuit is providedwith a switch SSW8 to continue the circuit to the main motor M1 when thecontacts 208 of switch SSW3 are opened.

The vibratory motor circuit 202 is energized through lines 2193 and2115. Line 203 is provided with a manually operated switch S5 which isconnected to line 207, the circuit being continued through contacts 210and M1 to one line 269 leading to the light operated photoelectric relayPE. A second line 211 leading from the relay PE is connected to amanually operated switch S4 in line 204 which leads to the vibratorymotor 110. A return line 213 from the vibratory motor leads to the line205, as shown, to complete the circuit.

From the description thus far it will be seen that in operation thevibrator motor is automatically started When the float ball 184 moves toa lowered position to rock the plate 198 out of the path of the lightbeam, and conversely, when the float ball rises, the plate is rockedinto the path of the beam to discontinue the feed of the adhesivepellets. A manually operated switch PB6 in line 215 is provided forconvenience to operate the vibrator motor in response to a demand foradhesive when the clutch operated switch SSW3 is opened. It will be seenthat closing of switch P86 will operate the vibrator independently ofthe operation of the main machine when the relay PE is energized. Theswitch S4 comprises a toggle switch for convenience of the operator todiscontinue the feed of pellets when desired. It will also be observedthat if the light source or relay fails the vibrator feed will notoperate.

The switch SSW8 comprises an overload safety switch arranged to beopened to open the circuit to the main motor in the event that anoverload occurs in the drive to the adhesive applying roll. Asillustrated in FIGS. 2 and 3, the chain and sprocket drive 28 isconnected to the shaft 96 by a separable drive connection or overloadsafety arranged to be disengaged in the event of an overload. Thesprocket of the drive connection is formed integrally with a disk 216and is mounted to rotate freely on a sleeve 218 keyed to the end of theshaft 96. The outer end of the sleeve 218 is provided with a head 220having a notch 222 out in the periphery thereof. A drive lug 224 carriedby an arm 226 pivotally mounted at 228 is spring urged into engagementwith a notch 222. The side walls of the notch and the drive lug aretapered as shown so that in the event of an overload the lug will beforced out of driving engagement with the notch. In order to hold thelug carrying arm 226 in its outwardly rocked position so that the lugwill not reengage with the notch upon completion of one revolution, aspring urged hooked member 230 is arranged to engage a latch member 232carried by the lug carrying arm 226 when the latter is rocked out ofdriving engagement. The hook member 230 is provided with a handle 234for manually releasing the latch 232 after the overload condition hasbeen corrected.

As shown in FIG. 2, the switch SSWS is disposed adjacent the overloadsafety drive connection and is provided with an arm 236 which carries aroller 238 arranged to be engaged by a portion 240 of the lug carryingarm 226 when the latter is rocked out of driving engagement andcontinues its rotation to engage the roller 23%. The switch SSWS isnormally in its closed position and when engaged by portion 240 isopened to open the circuit to the main drive motor as described.

The circuits to the heating elements in the melting chamber, the liquidchamber and the adhesive applying roll will now be described. Asillustrated in FIG. 6, the heating elements 114, 116 in the meltingchamber are energized through lines 2%, 295 as controlled by athermostat T53 upon closing of manually operated switch S2 in line 203.The circuit is continued through lines 242, 244, thermostat T83 andelements 114, 116. Line 246, leading from the elements, is connected tothe return line 295 as shown. The elements 126, 128, 130, 132 are alsoenergized through lines 203, 265 as controlled by thermostat TS2 andrelay MCZ. A line 248 from switch S2 is connected through the thermostatT52 to the relay MC2, the circuit being completed through return line205. Energization of relay MCZ will effect closing of contacts MC2 inline 259 to energize the heating elements 126, 128, 130, 132 as shown.

The heating coil indicated diagrammatically at 164 in FIG. 6 and whichis disposed within the hollow adhesive applying roll 22 is arranged inthe circuit to maintain a relatively high heat during operation of thedevice and to maintain a relative low heat when the device istemporarily idled or stopped. It will be understood that in operationall of the heating elements are activated a considerable period of timeprior to starting the packaging machine in operation for the purpose ofheating the adhesive to the proper temperature to permit a free flow ofthe same. During the preliminary warm up time, prior to starting theadhesive applying operation, it is preferred to maintain the applyingroller 22 at a low temperature so that burning or charring of theadhesive in engagement with the roll is avoided. Thereafter, when themachine is started and the adhesive applying device is activated it ispreferred to maintain the applying roll at a high temperature. Duringoperation of the device with the roll at a high temperature, some of theheat is dissipated upon engagement of the roll with the carton flaps sothat charring or burning of the adhesive in contact with the roll isavoided.

As illustrated in FIG. 6, when the machine is idle, that is, when theswitch contacts 210 of switch SSW3 are open, as shown, the heating coil164 is heated through a variable autotransformer AT2, the transformerbeing connected to the heating coil through normally closed relaycontacts MC3. The lines to the transformer AT2 include line 203 throughswitch S5 and line 207 to line 252 connected to one end of thetransformer, the other end thereof being connected by line 254 to thereturn line 213. The connection from the transformer AT2 to the heatingcoil 164, comprises a line 256 in which the normally closed contacts MC3and the coil 164 are connected, the coil being also connected to thereturn line 213.

When a sufficient time has elapsed to effect preheating of the adhesiveapplying device, the clutch is operated to close the contacts 210 ofswitch SSW3, and the main machine motor is started. Upon closing of thecontacts 210 a relay MC3 in line 215 is energized which operates to opennormally closed contacts MC3 in low heat transformer circuit and toclose the normally open contacts MC3 in the circuit of a second variableautotransformer AT3 adjusted to maintain a high temperature of the roll22. The transformer ATS is connected by a line 258from line 207 and by aline 260 to the return line 213. The heating coil 164 is thusautomatically connected to the high heat transformer AT3 by line 262 inwhich the normally open contacts MC3 are located. Conversely, when theclutch to the chain and sprocket drive 98 is disengaged and the contacts210 of switch SSW3 are opened, the relay MC3 will be deenergized and thecoil 164 will be automatically connected in the circuit to the low heattrans former AT2. As also shown in FIG. .6, a signal lamp LT2 isprovided in the vibrator circuit to indicate to the operator that thevibratory motor circuit is energized.

From the above description it willbe seen that the present adhesiveapplying device for a high speed packaging machine is adapted to apply aquick-setting adhesive to the top closing flaps of a carton during thecontinuous movement thereof so that when the adhesively coated flaps areclosed in overlapping relation they are quickly set in sealed engagementto provide an efiicient top closure, the advantage being that the usualelongated dryer for holding the flaps in sealing engagement until theseal is set is eliminated, resulting in a considerable saving of thespace required for the dryer. It will be further seen thatthe presentdevice provides novel means adapted to automatically feed adhesive tothe device in response to the demand therefor as the adhesive is used upwhereby to eliminate manual addition of adhesive to the supply.

While the preferred embodiment of the invention is herein illustratedand described, it will be understood that the invention may be embodiedin other forms within the scope of the following claims.

Having thus described the invention, what is claimed is: 1. In apackaging machine, in combination, conveying means for supporting andcontinuously advancing filled cartons having their top flaps arranged toreceive adhesive, adhesive applying means for applying a hot meltadhesive to selected of said flaps during the continuous r movement ofsaid cartons, said adhesive applying means comprising a continuouslyrotated and heated adhesive applying roll, a heated supply chambercontaining a supply of melted adhesive, means for transferring themelted adhesive from the supply chamber to the applying roll forapplication to said carton flaps, a heated melting chamber having aperforated bottom wall in communication with said supply chamber, meansfor feeding hot melt adhesive in solid form to said melting chamber tomelt and flow into said supply chamber, and control means includingmeans for detecting a depletion in the amount of adhesive in said supplychamber, and means responsive to said detecting means for actuating saidfeed- 1 ing means to restore the amount of adhesive in said supplychamber, said feeding means comprising a vibratory feeder having avibratory motor, a circuit for said vibratory motor, said control meansincluding a normally open switch in said circuitarranged to be closedupon detection of a depletion in the amount of adhesive in said supplychamber, a relay controlled main motor circuit for the packagingmachine, and normally open contacts in said vibratory motor circuitarranged to be closed when the main motor circuit is energized, and amanually operated switch by-passing said normally open main motorcircuit contacts for energizing said vibratory motor circuitindependently of said main motor circuit.

2. A packaging machine as definedin claim 1 wherein said melting chamberis disposed above said supply chamber, and an inclined passagewaybetween said chambers.

3. A packaging machine as defined in claim 1 wherein said adhesiveapplying roll is provided with patterned areas for applying adhesiveonto selected areas of the flaps, and driving means for said adhesiveapplying ro-ll arranged to rotate the roll at a peripheral speed equalto the linear speed of said conveying means and in timed relation to thecontinuous movement of said cartons to effect registration of saidpatterned areas with the selected areas of said flaps.

4. In a packaging machine, in combination, conveying means forsupporting and continuously advancing filled cartons having their topflaps arranged to receive adhesive, adhesive applying means for applyinga hot melt adhesive to selected of said flaps during the continuousmovement of said cartons, said adhesive applying means comprising acontinuously rotated and heated adhesive applying roll, 'a heated supplychamber, means for transferring the melted adhesive from the supplychamber to the applying roll for application to said carton flaps, aheated melting chamber having a perforated bottom wall in communicationwith said supply chamber, means for feeding hot melt adhesive in solidform to said melting chamber to melt and flow into said supply chamber,control means including means for detecting a depletion in the amount ofadhesive in said supply chamber, means responsive to said detectingmeans for actuating said feeding means to restore the amount of adhesivein said supply chamber, a heating circuit, a heating element for saidapplying roll, means for maintaining said element at a relatively lowtemperature when said applying roll is idle, and means for maintainingsaid element at a higher temperature when said roll is rotated, said lowand high temperature means including a low heat transformer inconnection with said heating element when the roll is idle, a high heattransformer in connection with said element when the roll is rotated,and means including a switch in said circuit arranged to be closed uponrotation of said roll for shifting the connection from said low heat tosaid high heat transformer.

5. In a packaging machine, in combination, conveying means forsupporting and continuously advancing filled cartons having their topflaps arranged to receive adhesive, adhesive applying means for applyinga hot melt adhesive to selected of said flaps during the continuousmovement of said cartons, said adhesive applying means comprising acontinuously rotated and heated adhesive applying roll, a heated supplychamber containing a supply of melted adhesive, means for transferringthe melted adhesive from the supply chamber to the applying roll forapplication to said carton flaps, a heated melting chamber having aperforated bottom wall in communication with said supply chamber, meansfor feeding hot melt adhesive in solid form to said melting chamber tomelt and flow into said supply chamber, and control means includingmeans for detecting a depletion in the amount of adhesive in said supplychamber, and means responsive to said detecting means for actuating saidfeeding means to restore the amount of adhesive in said supply chamber,said solid adhesive being in the form of ellets, said feeding meanscomprising a vibratory feeder having a vibratory motor, a circuit forsaid motor, said control means including a normally open switch in saidcircuit, said detecting means comprising a float ball in said supplychamber, and connections to said float ball for operating said switch toinitiate the feeding operation when the adhesive is depleted below apredetermined level, and to discontinue the feeding operation when theadhesive is restored to said level.

References Cited UNITED STATES PATENTS 2,301,136 11/1942 Moreland et al.222-56 2,693,429 11/1954 Radtke et 211.

2,764,123 9/1956 Derderian 118216 3,030,915 4/1962 Shannon 1182023,050,756 8/1962 Kamborian.

3,135,628 6/1964 Johnson et a1.

3,237,593 3/1966 Trotter 118-7 3,279,425 10/1966 Gottscho 118-261CHARLES A. WILLMUTH, Primary Examiner.

R. I. SMITH, Assistant Examiner.

1. IN A PACKAGING MACHINE, IN COMBINATION, CONVEYING MEANS FORSUPPORTING AND CONTINUOUSLY ADVANCING FILLED CARTONS HAVING THEIR TOPFLAPS ARRANGED TO RECEIVE ADHESIVE, ADHESIVE APPLYING MEANS FOR APPLYINGA HOT MELT ADHESIVE TO SELECTED OF SAID FLAPS DURING THE CONTINUOUSMOVEMENT OF SAID CARTONS, SAID ADHESIVE APPLYING MEANS COMPRISING ACONTINUOUSLY ROTATED AND HEATED ADHESIVE APPLYING ROLL, A HEATED SUPPLYCHAMBER CONTAINING A SUPPLY OF MELTED ADHESIVE, MEANS FOR TRANSFERRINGTHE MELTED ADHESIVE FROM THE SUPPLY CHAMBER TO THE APPLYING ROLL FORAPPLICATION TO SAID CARTON FLAPS, A HEATED MELTING CHAMBER HAVING APERFORATED BOTTOM WALL IN COMMUNICATION WITH SAID SUPPLY CHAMBER MEANSFOR FEEDING HOT MELT ADHESIVE IN SOLID FORM TO SAID MELTING CHAMBER TOMELT AND FLOW INTO SAID SUPPLY CHAMBER, AND CONTROL MEANS INCLUDINGMEANS FOR DETECTING A DEPLETION IN THE AMOUNT OF ADHESIVE IN SAID SUPPLYCHAMBER, AND MEANS RESPONSIVE TO SAID DETECTING MEANS FOR ACTUATING SAIDFEEDING MEANS TO RESTORE THE AMOUNT OF ADHESIVE IN SAID SUPPLY CHAMBER,SAID FEEDING MEANS COMPRISING A VIBRATORY FEEDER HAVING A VIBRATORYMOTOR, A CIRCUIT FOR SAID VIBRATORY MOTOR, SAID CONTROL MEANS INCLUDINGA NORMALLY OPEN SWITCH IN SAID CIRCUIT ARRANGED TO BE CLOSED UPONDETECTION OF A DEPLETIN IN THE AMOUNT OF ADHESIVE IN SAID SUPPLYCHAMBER, A RELAY CONTROLLED MAIN MOTOR CIRCUIT FOR THE PACKAGINGMACHINE, AND NORMALLY OPEN CONTACTS IN SAID VIBRATORY MOTOR CIRCUITARRANGED TO BE CLOSED WHEN THE MAIN MOTOR CIRCUIT IS ENERGIZED, AND AMANUALLY OPERATED SWITCH BY-PASSING SAID NORMALLY OPEN MAIN MOTORCIRCUIT CONTACTS FOR ENERGIZING SAID VIBRATORY MOTOR CIRCUITINDEPENDENTLY OF SAID MAIN MOTOR CIRCUIT.